Wrapping up the school year, traveling in the Midwest, two retreats, and planning for the next year have kept me busy. Not too busy to explore math. In the spring, I started learning Javascript, a computer language to make webpages more interesting. I made the curve stitching on the left in less than ten lines of code! Javascript came in handy for making illustrations for a workshop on finding joy in mathematics.

I began thinking about precalculus while making this half of a hyperbola. It struck me that, to some people, curves are no more than objects of fear rather than delight. Images linked to ugly formulas to be memorized, attached to definitions for bizarre words like conic section, asymptote, vertex, focal point, axis of symmetry, and reflection. Even people who had passed calculus in college did not see the connection between curve stitching and high- level mathematics. They remember memorizing facts divorced from concepts. Even in math,

*ideas*must be clothed with facts as they occur.Isn't this cat's eye lovely?

To make this, I reflected the half hyperbole along a line between the corners of the eye. I resurrected foggy notions of the Cartesian coordinate system (x-axis versus y-axis). Through trial and error —

To make this, I reflected the half hyperbole along a line between the corners of the eye. I resurrected foggy notions of the Cartesian coordinate system (x-axis versus y-axis). Through trial and error —

**math people never do things correctly the first time****— I figured out that swapping the x and y values. It was tricky. I couldn't apply precalculus rules for transformation since Javascript grids are different. The origin (0, 0) is the upper left corner of the square and (400, 400) is the lower right corner. I had to play!**Then, I went curve stitching crazy! I made a fancy frame with two cat's eyes with lines of symmetry that make right angles (or form perpendicular lines). Again, this was an exercise in trial and error. It took me even longer to figure out I needed to swap x and y at one point, instead of both.

I know! Too many facts. Playing with curves invites ideas. Putting them together differently leads to beautiful designs. Figuring out how to code them has caused deep thinking. Curve stitching inspires wonder and encourages questions to be asked and answered years before taking precalculus.

I know! Too many facts. Playing with curves invites ideas. Putting them together differently leads to beautiful designs. Figuring out how to code them has caused deep thinking. Curve stitching inspires wonder and encourages questions to be asked and answered years before taking precalculus.

I wanted to write Javascript for a cross. I randomly tried one variation after another and wasted an hour making a mess! Then, I took a break and started over.

I began to think. What if I made a frame that looks like an old-fashioned television screen?

The four pieces (one per corner) would be half the size of those on the fancy frame. This step points to a key element of problem-solving: break the process down into smaller steps and conquer the problem one step at a time.

I began to think. What if I made a frame that looks like an old-fashioned television screen?

The four pieces (one per corner) would be half the size of those on the fancy frame. This step points to a key element of problem-solving: break the process down into smaller steps and conquer the problem one step at a time.

The final step is simply a matter of moving pieces vertically and horizontally. Look at the upper left corner of the television screen. Imagine where that piece belongs in the cross IF you don't rotate it or flip it. You put your finger in the corner of the piece. You push it halfway down the television screen and halfway across. Put your finger on the image on your computer screen if you must. Can you see it?

If not, make a quick sketch of the television screen and cut it out along the edge. Cut it into four equal pieces. Treat the pieces like manipulatives and make a cross by moving them.

If not, make a quick sketch of the television screen and cut it out along the edge. Cut it into four equal pieces. Treat the pieces like manipulatives and make a cross by moving them.

The final design places the cross inside the television screen. In Javascript, I simply put the lines of code for eight pieces in the same loop. What looks complicated was easy!

Then, I realized something! When tutoring someone in precalculs, I looked up how to change a formula to shift the curve to another point. This tangible process helped me see that all you need to do is adding a positive or negative number to the original coordinates. Reflection requires the x and y coordinates to swap places. From now on, all I need to do is recall curve stitching!

Then, I realized something! When tutoring someone in precalculs, I looked up how to change a formula to shift the curve to another point. This tangible process helped me see that all you need to do is adding a positive or negative number to the original coordinates. Reflection requires the x and y coordinates to swap places. From now on, all I need to do is recall curve stitching!

Curve stitching is a lot of fun. My friend Bobby Jo, a homeschooler who introduced me to paper sloyd, captioned a picture of my original Valentine cards as “Sloyd marries curve stitching" Math + Handcraft heaven.

How do you start? Here is a quick tour. First read my post, Curve Stitching Roundup, an orderly review of what curve stitching is, who invented it, and interesting variations. Since that post, I've added a few elaborations: six-petal flower, picture frame, valentine I, valentine II, and valentine III.

How do you start? Here is a quick tour. First read my post, Curve Stitching Roundup, an orderly review of what curve stitching is, who invented it, and interesting variations. Since that post, I've added a few elaborations: six-petal flower, picture frame, valentine I, valentine II, and valentine III.